Haha him being incosistent in the past is absolutely normal. He just turned 23, 2 June, not every player can be like R9 or Messi (as in, consistently world-class at a very young age). Cristiano didn't become world-class until he was 23 and look at him now. Or what about Dinho and Zidane? And no I'm not saying Aguero will reach that level with all certainty, though he has all the talent to do so. And his goal-scoring record, see Terry07's post, is highly impressive for someone was 18-22 during that time, mostly playing as a second striker and not even playing for a world-class side. He was absolutely class last season, and that in a poor Atletico side.